package com.example.util;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class Base64Util {
    /**
     * 本地图片转换成base64字符串
     * @param imgFile	图片本地路径
     * @return
     *
     * @author ZHANGJL
     * @dateTime 2018-02-23 14:40:46
     */
    public static String ImageToBase64ByLocal(String imgFile) {

        InputStream in = null;
        byte[] data = null;

        // 读取图片字节数组
        try {
            in = new FileInputStream(imgFile);

            data = new byte[in.available()];
            in.read(data);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try{
                if (in != null) {
                    in.close();
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data);// 返回Base64编码过的字节数组字符串
    }



    /**
     * 在线图片转换成base64字符串
     * @param imgURL	图片线上路径
     * @return
     * @author ZHANGJL
     * @dateTime 2018-02-23 14:43:18
     */
    public static String ImageToBase64ByOnline(String imgURL) {
        ByteArrayOutputStream data = new ByteArrayOutputStream();
        InputStream is = null;
        try {
            // 创建URL
            URL url = new URL(imgURL);
            byte[] by = new byte[1024];
            // 创建链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5000);
            is = conn.getInputStream();
            // 将内容读取内存中
            int len = -1;
            while ((len = is.read(by)) != -1) {
                data.write(by, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try{
                if (is != null) {
                    is.close();
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data.toByteArray());
    }


    /**
     * base64字符串转换成图片
     * @param imgStr		base64字符串
     * @param imgFilePath	图片存放路径
     * @return
     *
     * @author ZHANGJL
     * @dateTime 2018-02-23 14:42:17
     */
    public static boolean Base64ToImage(String imgStr,String imgFilePath) {

        if (StringUtil.isEmpty(imgStr)) { // 图像数据为空
            return false;
        }
        OutputStream out = null;
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // Base64解码
            byte[] b = decoder.decodeBuffer(imgStr);
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {// 调整异常数据
                    b[i] += 256;
                }
            }
            out = new FileOutputStream(imgFilePath);
            out.write(b);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try{
                if (out != null) {
                    out.flush();
                    out.close();
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        return true;
    }
}
